Anomalous valley Hall effect in antiferromagnetic monolayers

TL;DR

This paper proposes a new method to realize and control the anomalous valley Hall effect in antiferromagnetic monolayers through stacking and ferroelectric polarization, expanding understanding of AVH phenomena.

Contribution

It introduces a general design principle for AVH in antiferromagnetic monolayers and demonstrates its feasibility via first-principles calculations.

Findings

AVH effect can be realized in antiferromagnetic monolayers.

Stacking pattern modulates the AVH effect.

Ferroelectric polarization switching controls AVH on/off states.

Abstract

Anomalous valley Hall (AVH) effect is a fundamental transport phenomenon in the field of condensed-matter physics. Usually, the research on AVH effect is mainly focused on 2D lattices with ferromagnetic order. Here, by means of model analysis, we present a general design principle for realizing AVH effect in antiferromagnetic monolayers, which involves the introduction of nonequilibrium potentials to break of PT symmetry. Using first-principles calculations, we further demonstrate this design principle by stacking antiferromagnetic monolayer MnPSe3 on ferroelectric monolayer Sc2CO2 and achieve the AVH effect. The AVH effect can be well controlled by modulating the stacking pattern. In addition, by reversing the ferroelectric polarization of Sc2CO2 via electric field, the AVH effect in monolayer MnPSe3 can be readily switched on or off. The underlying physics are revealed in detail. Our findings open up a new direction of research on exploring AVH effect.